Fire-ant scourge proves difficult to eradicate

SYLVIA MORENOThe Washington Post

Published Tuesday, April 19, 2005

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CHARLES L. BARR, a fire ant specialist with the Texas Cooperative Extension, pokes a fire ant mound at Lockhart Municipal Airport, where he is conducting an extermination experiment. About 300 million acres in the United States are infested with red imported fire ants.

Barr didn't have to look far. April marks the beginning of fire ant season, when warm weather brings the ants above ground where they build dirt mounds that dot the Texas landscape like a terrestrial pox.

Mound after mound swarmed with thousands of tiny angry ants, reacting to Barr's low-tech discovery method. Wearing an Australian bush hat and thick leather boots, Barr stuck the sharpened end of a wooden pole into a pile of dirt and gave it a sharp twist. He bent his head toward the ground and squinted hard at the mound, looking for telltale signs of scurrying ants.

He found plenty, but there was a little hope in the meadow land alongside the one concrete runway that defines Lockhart Municipal Airport. A few mounds appeared to be ant-less and others yielded only a few hundred ants due to Barr's latest eradication experiment. Barr had estimated that 90 million fire ants live on the 12-acre airport property (not really much of an ant problem compared with some parts of Texas, he assured the airport manager), and he was determined to kill off some of them.

Barr is a fire ant specialist with the Texas Cooperative Extension at Texas A&M University, and his job is to test the latest pesticides and application methods designed to get rid of the scourge of the South. He has been on this quest for the past 16 years.

"We're not expecting miracles," Barr said of his latest eradication test. "We're just looking for another weapon in the arsenal."

Northerners interested in moving to the Sun Belt better learn about what the pesticide industry and entomologists have dubbed the Fire Ant Belt, the swath of states south from North Carolina and west to Texas. About 300 million acres in the United States are infested with red imported fire ants, which are believed to have arrived in Mobile, Ala., in the 1930s in the cargo hold of ships from South America. They have no native predators and have been shielded from the harshest sure-acting pesticides since the mid-1980s by the Environmental Protection Agency. They have an ingenious ability to survive by molding themselves into living rafts during floods and floating along until they find dry land to build their colonies anew. So they have thrived.

The rust-colored ants, with their black abdomens, range in size from three-sixteenths to a quarter of an inch long. But their effect can be devastating, as they sometimes overwhelm and kill newly born livestock and wildlife and even fragile nursing home residents with their poisonous bites. Scientists at last month's annual Imported Fire Ant Conference in Gulfport, Miss., reported that 80 human deaths -- including five in nursing homes -- have been attributed to anaphylactic shock from fire ant bites while 42 percent of visits to venom clinics have been because of fire ant stings.

In addition to mammals, fire ants like electricity. They eat through cable insulation on power lines and congregate on metal conductors, causing shorts in electrical lines, junction boxes, traffic and street lights, and air conditioners. What Cheryl Hill-Burrier, manager of Lockhart Airport, fears most is losing her radio system to the ants.

"They love the wire that goes to my radio. I don't know why, but they do," she said, pointing to the cable behind her desk and a large dark brown pile of dead ants on the carpet. She had to pull out the pesticide spray that morning. "I worry about that. I am the tower to the pilots."

California discovered fire ants several years ago and had mixed success with a statewide eradication program, and just two months ago, officials in Las Cruces, N.M., found them in a city park along the Rio Grande. The city closed the four-acre park for more than a month and conducted an aggressive chemical eradication program. They measured a 93 percent "die-off," acting parks department manager Carlos Madrid said. However, all produce and plants grown in Dona Ana County, where Las Cruces is located, remain under quarantine to make sure no tiny ants got into any farm or nursery soil.

that is destined for out of state. "We're really hoping we got it," Madrid said.

Hong Kong, China and Taiwan have recently sent scientists to Texas to study eradication methods after discovering fire ants. A Taiwanese researcher has followed around members of a Round Rock homeowners association in their communal quest to get rid of the fire ants plaguing their suburban Austin green belt, community park and yards.

Australia, which discovered its first fire ant mound in early 2001, invited Barr to provide some expertise, but even before he arrived, officials had launched a $175 million eradication program. They have called the fire ant the greatest ecological threat to Australia since the introduction of the rabbit and have vowed, as their slogan says, to "Find the Last Fire Ant."